NERVOUS SYSTEM OF INSECTS. 319 
the antennal nerves (Fig. 276, af). The simple brain of the 
locust may be compared with the more complicated brain of 
an ant, as seen in Vig. 279. 
The infra-cesophageal ganglion (Fig. 278, if), as its name 
implies, lies under the esophagus at the base of the head, un- 
Fig, 279.—Right half of an ant’s-brain: “@, infra-eesophageal ganglion; @r, brain; 
€, central connective portions ; W, semi-circular bodies of the small-celled portion 
of the brain lying next to the basal portion of the brain, from which the nerves to the 
simple eyes (au) arise; Au, optic lobes ; An, antennal lobes (the bodies appearing 
like cells are rounded masses of the network of the substance of the cord; 7, cellu- 
Jar cortical substance of the brain; ko, twofold body of the commissure connecting 
the brain wih the infra-cesophageal ganglion.—After Leydig, from Graber. 
der abridge of chitine, and directly behind the tongue. It is 
connected with the supra-cesophageal ganglion by two com- 
missures passing up each side of the esophagus. From the 
ander side of the infra-cesophageal ganglion arise three 
pairs of nerves, which are distributed to the mandibles. 
